BB lab 1

• What is immunohematology?

  It is the study of blood group antigens and antibodies.
• What does blood banking refer to?

  It refers to the process of collecting, separating, and storing blood.
• What is an immunogen?

  An immunogen is an antigen that is capable of eliciting an immune response.
• What factors contribute to immunogenicity?

  • Molecular size
  • Chemical composition and complexity
  • Conformation
  • Accessibility
  • Charge
  • Digestibility
  • Degree of foreignness
  • Dosage and antigen density
  • Route of administration
• What are the general properties of antibodies?

  • Immunoglobulins are glycoproteins secreted by plasma cells
  • Bind to specific epitopes on antigens
  • Five classifications: IgG, IgA, IgM, IgD, IgE
  • Concentration in serum: IgG > IgA > IgM > IgD > IgE
  • Functions include binding antigens, fixing complement, facilitating phagocytosis, and neutralizing toxins
• What is the major immunoglobulin in normal serum?

  Immunoglobulin G (IgG).
• What is the significance of IgG antibodies in transfusion medicine?

  IgG antibodies are important in transfusion medicine and Hemolytic Disease of the Fetus and Newborn (HDFN).
• What is the concentration of IgM in the immunoglobulin pool?

  6% of the immunoglobulin pool.
• What is the primary form of IgM?

  IgM exists in both monomeric and polymeric forms (as pentamers).
• Where is secretory IgA usually found?

  Secretory IgA is usually found in the mucosal tissues of the body.
• What are the characteristics of naturally occurring and immune antibodies?

  • Naturally occurring antibodies:
  • Found in individuals never exposed to RBC antigens
  • Mostly IgM
  • Commonly react with ABO and H, Ii, Lewis, MN, and P blood group systems
  • Immune antibodies:
  • Found in individuals who have been transfused or pregnant
  • Mostly IgG
  • Commonly react with Rh, Kell, Duffy, Kidd, and Ss blood group systems
• What are unexpected antibodies also known as?

  Irregular or atypical antibodies.
• What are alloantibodies?

  Alloantibodies are produced after exposure to genetically different antigens.
• What are autoantibodies?

  Autoantibodies are produced in response to self-antigens.
• What is the basic procedure in immunohematology?

  • Source of antibody + source of antigen → Ag-Ab reaction
• Where are red cell antigens and antibodies located?

  • Red cell antigens are located on the red cells, part of the cell membrane.
  • Red cell antibodies are molecules in the plasma or serum.
• What are the sources of antigen and antibody for testing in agglutination reactions?

  • Known source:
  • Antigen: Reagent red cells
  • Antibody: Commercial antisera
  • Unknown source:
  • Antigen: Patient or donor red cells
  • Antibody: Patient or donor serum/plasma
• What are the routine testing procedures in the immunohematology laboratory?

  • ABO/D typing (forward grouping)
  • ABO serum (reverse grouping)
  • Antibody screen
  • Antibody identification
  • Crossmatch
• What is the purpose of the ABO/D typing procedure?

  It detects A, B, and D antigens.
• What is the purpose of the antibody screen?

  It detects antibodies with specificity to red cell antigens.
• What are the differences between polyclonal and monoclonal antibody reagents?

  • Polyclonal:
  • Produced from several different clones of B cells
  • Heterogeneous population of antibodies
  • Monoclonal:
  • Produced from a single clone of B cells
  • Unique specificity for a particular epitope
• What is the advantage of monoclonal antibody reagents?

  They produce large quantities of the desired antibody with lot-to-lot consistency.
• What is a disadvantage of monoclonal antibody reagents?

  They may have overspecificity and oversensitivity.
• What are the categories of reagents used in blood banking?

  • Antisera: known red cell antibodies
  • Reagent red cell: known red cell antigens
  • Antiglobulin reagents
  • Antibody potentiators or enhancement media
  • Lectins
• What is the purpose of antiglobulin reagents?

  They contain antibodies that react with IgG or complement.
• What are antibody potentiators?

  Commercially available reagents used to enhance detection of IgG antibodies.
• What are some examples of antibody potentiators?

  • Antiglobulin reagents
  • Low-Ionic-Strength Saline (LISS) solution
  • Polyethylene Glycol
  • Enzymes (Papain, Ficin, Bromelin)
  • Bovine Serum Albumin (22% or 30%)
• What are lectins used for in blood banking?

  • Plant extracts useful as an alternative to antisera for blood typing.